Cushion inside a cushion patient interface

ABSTRACT

A patient interface device including a cushion assembly having a cushion-in-a-cushion arrangement and a system for supplying a flow of gas to a patient using such an interface device. The patient interface includes a mask shell having a patient side and an outer side opposite the patient side adapted for receiving a supply of gas. A seal cushion contacts a first area of a patient&#39;s face to form a seal therewith. A support cushion is disposed outside the seal cushion and includes a first end portion that contacts a second area of a patient&#39;s face.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a Continuation under 35 U.S.C. §120 of U.S. patentapplication Ser. No. 11/875,496, filed Oct. 19, 2007, which is aContinuation under 35 U.S.C. §120 of U.S. patent application Ser. No.11/401,065, filed Apr. 10, 2006, now U.S. Pat. No. 7,287,528, whichclaims priority under 35 U.S.C. §119(e) from provisional U.S. patentapplication No. 60/670,806 filed Apr. 13, 2005 the contents of which areincorporated herein by reference.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention generally relates to a patient interface devicefor use in a pressure support system that supplies a flow of gas to theairway of a patient, and, in particular to a patient interface devicethat includes dual-cushion support and to a pressure support system thatincludes such a patient interface device.

2. Description of the Related Art

There are numerous situations where it is necessary or desirable todeliver a flow of breathing gas non-invasively to the airway of apatient, i.e., without intubating the patient or surgically inserting atracheal tube in their esophagus. For example, it is known to ventilatea patient using a technique known as non-invasive ventilation (NIV). Itis also known to deliver continuous positive airway pressure (CPAP) orvariable airway pressure, such as a bi-level pressure that varies withthe patient's respiratory cycle or an auto-titrating pressure thatvaries with the monitored condition of the patient. Typical pressuresupport therapies are provided to treat a medical disorder, such assleep apnea syndrome, in particular, obstructive sleep apnea (OSA),chronic obstructive pulmonary disease (COPD), or congestive heartfailure (CHF).

Non-invasive ventilation and pressure support therapies involve theplacement of a patient interface device, which is typically a nasal ornasal/oral mask, on the face of a patient to interface the ventilator orpressure support system with the airway of the patient so that a flow ofbreathing gas can be delivered from the pressure/flow generating deviceto the airway of the patient. It is known to maintain such masks on theface of a patient by a headgear having upper and lower straps, eachhaving opposite ends threaded through connecting elements provided onthe opposite sides and top of a mask.

Typically patient interface devices include a mask shell having acushion attached to the shell that contacts the surface of the patient.The mask shell and cushion are held in place by a headgear that wrapsaround the head of the patient. The mask and headgear form the patientinterface assembly. A typical headgear includes flexible, adjustablestraps that extend from the mask to attach the mask to the patient.

Because such masks are typically worn for an extended period of time, avariety of concerns must be taken into consideration. For example, inproviding CPAP to treat OSA, the patient normally wears the patientinterface device all night long while he or she sleeps. One concern insuch a situation is that the patient interface device is as comfortableas possible, otherwise the patient may avoid wearing the interfacedevice, defeating the purpose of the prescribed pressure supporttherapy. It is also important that the interface device provide a tightenough seal against a patient's face without discomfort. A problemarises in that in order for the mask to maintain a seal without anyundue gas leaks around the periphery of the mask, the mask may becompressed against the patient's face.

Many patient interface devices have been developed that attempt tobalance the competing interests of patient comfort versus minimizingleakage. In addressing this issue, many patient interface devices havefocused on the design of the cushion. Early cushion designs weretypically a flap of material or a balloon, i.e., air-filled cushion,that contacted the face of the user. Further design developmentsincluding contouring the patient contacting portion of the cushionand/or making the seal customizable to the surface or underlying tissuesof the user. Still further cushions have employed multiple flaps so thatthe outermost flap provides a sealing function. See, e.g., U.S. Pat. No.4,791,051 to Toffolon.

Although these conventional patient interface devices have advanced theart, the need still exists for a patient interface device that improvesupon existing devices, for example, to maximize patient comfort whileminimizing leak, during delivery of a positive airway pressure or flowof gas to the airway of the user. For example, many conventional patientinterface devices tend to focus the strapping force applied on thepatient to a relative small area of the patient's face around the nose,mouth, or both. Existing patient interfaces also may not provide astable platform that supports the cushion on the patient's face.

SUMMARY OF THE INVENTION

Accordingly, it is an object of the present invention to provide apatient interface device that overcomes the shortcomings of conventionalpatient interface devices. This object is achieved according to oneembodiment of the present invention by providing a patient interfacedevice that includes a mask shell, a seal cushion, and a supportcushion. The seal cushion has a first end portion that contacts a firstarea of a patient's face to form a seal against the user's skin and asecond end portion opposite the first end portion. The seal cushionfurther includes a cavity adapted to receive a portion of the patient'sface. Gas entering the mask for delivery to the user is received in thiscavity. The support cushion encircling a perimeter of the seal cushionand has a first end portion that contacts a second area of a patient'sface and a second end portion opposite the first end portion. The secondend portion of the seal cushion and the second end portion of thesupport cushion are coupled to the patient side of the mask shell.

It is yet another object of the present invention to provide a systemfor delivering a flow of gas to a patient that includes such a patientinterface device.

These features and characteristics of the present invention, as well asthe methods of operation and functions of the related elements ofstructure and the combination of parts and economies of manufacture,will become more apparent upon consideration of the followingdescription and the appended claims with reference to the accompanyingdrawings, all of which form a part of this specification, wherein likereference numerals designate corresponding parts in the various figures.It is to be expressly understood, however, that the drawings are for thepurpose of illustration and description only and are not intended as adefinition of the limits of the invention. As used in the specificationand in the claims, the singular form of “a”, “an”, and “the” includeplural referents unless the context clearly dictates otherwise.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a perspective view of a patient interface device according tothe principles of the present invention shown (schematically) connectedto a gas flow/pressure generating system;

FIG. 2 is an exploded view of the patient interface device of FIG. 1;

FIG. 3 is a front view of the patient interface device of FIG. 1;

FIG. 4 is a sectional view of the patient interface device of FIG. 1taken along line 4-4 of FIG. 3;

FIG. 5 is an exploded view of a patient interface device according to asecond embodiment of the present invention;

FIG. 6 is a front view of the patient interface device of FIG. 5;

FIG. 7 is a sectional view of the patient interface device of FIG. 5taken along line 7-7 of FIG. 6;

FIG. 8 is a side sectional view of the patient interface device of FIG.5;

FIGS. 9 and 10 are front and rear perspective views, respectively, of apatient interface device according to third embodiment of the presentinvention;

FIG. 11 is a detailed sectional view showing an exemplary technique forattaching a seal member to a flexible connecting member; and

FIG. 12 is a side sectional view of a patient interface device accordingto fourth embodiment of the present invention.

DETAILED DESCRIPTION OF THE EXEMPLARY EMBODIMENTS

In describing the illustrated exemplary embodiments of the presentinvention, the terms “upper” and “lower” refer to the orientation of themask as illustrated in the accompanying drawings. FIGS. 1-4 illustratean exemplary first embodiment of a patient interface device 10 accordingto the principles of the present invention. Patient interface device 10communicates a flow of breathing gas between the patient's airway and apressure/flow generating system 12, such as a ventilator, CPAP device,or variable pressure device, e.g., a BiPAP® device manufactured anddistributed by Respironics, Inc. of Pittsburgh, Pa., or anauto-titration pressure support system.

A BiPAP® device is a bi-level device in which the pressure provided tothe patient varies with the patient's respiratory cycle, so that ahigher pressure is delivered during inspiration than during expiration.An auto-titration pressure support system is a system in which thepressure varies with the condition of the patient, such as whether thepatient is snoring or experiencing an apnea or hypopnea. For presentpurposes, pressure/flow generating system 12 is also referred to as agas flow generating device, because flow results when a pressuregradient is generated. The present invention contemplates thatpressure/flow generating system 12 is any conventional system fordelivering a flow of gas to an airway of a patient or for elevating apressure of gas at an airway of the patient, including the pressuresupport systems summarized above and non-invasive ventilation systems.

Communicating a flow of breathing gas between the patient's airway andpressure/flow generating system 12 includes delivering a flow ofbreathing gas to the patient from the pressure/flow generating deviceand exhausting a flow of gas from the patient to ambient atmosphere. Thesystem for delivering a breathing gas to a patient according to thepresent invention comprises the pressure/flow generating system thatproduces a flow of gas, and a conduit 14, which is also referred to as apatient circuit, having a first end portion operatively coupled to thegas flow generating device and a second end portion. Conduit 14 carriesthe flow of gas from pressure/flow generating device 12 during operationof the system to patient interface device 10, which is coupled to thesecond end portion of the conduit. Conduit 14 corresponds to any conduitsuitable for communicating the flow of gas form the pressure/flowgenerating system to the patient interface device. A typical conduit isa flexible tube. A headgear assembly, which is not shown in the figures,attaches patient interface device 10 to the patient's head.

Patient interface device 10 includes a cushion assembly, generallyindicated at 16, that includes an inner seal member or seal cushion 18and an outer support member or support cushion 20. The patient interfacedevice also includes a mask shell 22 and a conduit coupling member (notillustrated) that couples the mask shell to conduit 14 so that a flow ofgas is communicated to the interior of the patient interface device forsubsequent delivery to the patient. Conversely, gas from the patient iscommunicated from the patient interface device into the conduit, wherean exhaust port is located.

In the illustrated exemplary embodiment, seal cushion 18 corresponds, ingeneral, to the cushion described in U.S. Pat. Nos. 6,651,663 and6,729,333, the contents of which are incorporated herein by reference.As perhaps best shown in FIG. 2, seal cushion 18 has a generallytriangular shape and is defined from a unitary piece of soft, cushiony,elastomeric material, such as silicone, appropriately soft thermoplasticelastomers, closed cell foam, thin materials, or any combination of suchmaterials. Seal cushion 18 has a first end portion 24 and a second endportion 26 generally opposite the first end portion. A nose receivingcavity 28 is defined in the interior of the inner seal member by a sidewalls 29.

First end portion 24 is adapted to contact an inner perimeter area ofthe patient's face and includes a first opening 30 to allow passage of aleast a portion of the patient's nose into nose receiving cavity 28. Inthe illustrated exemplary embodiment, first end portion 24 is contouredto match the generally facial features of a human. Seal cushion 18includes a base portion 32 defined in second end portion 26 and a secondopening 34 defined in base portion 32. First end portion 24 of sealcushion 18 includes a first in-turned flap 35 that has a distal edge,which is generally turned into nose receiving cavity 28, and a secondin-turned flap 37, which also has a distal edge that is generally turnedinto the nose receiving cavity. In the illustrated exemplary embodiment,flap 35 contacts the surface of the patient and deflects toward the nosereceiving cavity.

Flap 35 extends around the perimeter of the first end portion and isrelatively flexible to provide a leak resistant seal over the patientcontacting area of the seal cushion. Flap 37 extends around a largeportion of the perimeter of the first end portion, but is not present oris reduced in the area of the seal cushion that overlies the bridge ofthe user's nose. Flap 37 is relatively more stiff than flap 35 toprovide support for seal cushion as it is compressed. The stiffness offlap 37 and its separation from flap 35 establish the degree of supportprovided by flap 37. Where less support is needed, such as at the bridgeof the nose (and where sealing can be difficult) the distance betweenflap 35 and flap 37 is increased, for example by removing flap 37 inthis area. It can thus be appreciated that a variety of differentconfigurations for flaps 35 and 37 can be employed in the cushions ofthe present invention.

Mask shell 22 is a generally rigid shell, and, in an exemplaryembodiment of the present invention is formed from rigid plastic, suchas polycarbonate. Mask shell 22 includes a patient side 36 and oppositethereto, an outer side 38. Attached to outer side 38 of mask shell 22 isa conduit coupling member (not illustrated) for coupling the patientinterface device to delivery conduit 14.

In this embodiment, mask shell 22 has a generally triangular shapehaving a forehead support portion 40 that includes headgear attachingelements in the form of receiving holes or slots 42 disposed on eitherside of the upper forehead support portion for receiving headgear straps(not illustrated). In the illustrated embodiment, the lower corners ofmask shell 22 also include headgear attaching elements in the form ofsocket attachment elements 44, which cooperate with corresponding ballelements (not illustrated) on headgear straps. The ball and socketconfiguration, and other headgear attachment configurations suitable foruse with the present invention, are disclosed in co-pending U.S. patentapplication Ser. No. 10/629,366 (U.S. Pub. No. US-2004-0025883-A1), thecontents of which are incorporated herein by reference. It is to beunderstood that the present invention contemplates using anyconventional connection assembly to attach a headgear or headgear strapto mask shell 22 in this or any of the other embodiments.

The present invention contemplates that the headgear suitable for usewith patient interface device 10 is any conventional headgear used inthe patient interface field. For example, a typical headgear assemblycomprises a headpiece that overlies a portion of the patient's craniaand with headgear straps extending therefrom to adjustably connect theheadgear to the mask.

In the illustrated embodiment, seal cushion 18 is a nasal cushion,meaning that it seals around the nose of the user. It is to beunderstood, however, that the present invention contemplates that theseal cushion can seal around any portion of the patient. For example,the seal cushion can be a nasal pillow or nasal cannula that sealagainst the nose, an oral/nasal seal that seals around the mouth andnose, or an oral seal that seals around the mouth.

Support cushion 20 has a generally triangular shape having an elongatedupper corner. Support cushion 20 surrounds or encircles side walls 29 ofseal cushion 18 and includes an integrated forehead support portion 46at its upper extent. Support cushion 20 is preferably similar in form toa conventional mask cushion, such as a nasal or oral/nasal mask, whichcontacts the perimeter of a patient's facial area. Support cushion 20 ispreferably formed from a unitary piece of soft, cushiony, elastomericmaterial, such as silicone, appropriately soft thermoplastic elastomers,or gel materials. The flexibility of the material as well as thegeometry will allow support cushion 20 to conform to the patient'sfacial contours in a passive manner without noticeable adjustment.

Seal cushion 18 is structured to have a slightly higher profile thansupport cushion 20, see, e.g., FIG. 4. In use, seal cushion 18 willcompress slightly to form a seal with the patient's face, while supportcushion 20 will provide support over a relatively larger perimeter areaon the patient. This relatively large patient contacting area of thesupport cushion widely distributes the compressive forces acting on thepatient interface device to secure the patient interface device againstthe surface of the user.

Integrated forehead support portion 46 of support cushion 20 eliminatesthe need for a separate forehead cushion, as found in many commerciallyavailable masks. Forehead support portion 46 achieves a comfortablesupport for the forehead passively and without active adjustment,allowing an infinite number of position adjustments. The presentinvention, however, contemplates that support cushion 20 is formedwithout a forehead support portion such that the support stands-alonesupporting the nose or oral-nasal perimeter areas only.

Support cushion 20 has a first end portion 48 and a second end portion50 generally opposite the first end portion. A seal cushion receivingcavity 52 is defined by side walls 54. First end portion 48 is adaptedto generally contact an outer perimeter area of the patient's face, butis not necessarily in contact with the entire outer perimeter. That is,support cushion 20 need not serve as sealing member and does not providea leak resistant seal for the flow of gas to the airway of the patient.Nevertheless, the present invention contemplates that the supportcushion and the seal cushion can have similar configurations and be madefrom similar materials or combinations of materials. For example,support cushion 20 can include multiple flaps, lips, or rims at firstend portion 48 and the first end portion can be contoured to match thefacial features of a human, in general.

First end portion 48 also includes an in-turned flap 56, which isgenerally turned into seal cushion receiving cavity 52. The presentinvention also contemplates forming support cushion 20 from a solidformation, for example, from a gel material, or from a combination ofmaterials. First end portion 48 also includes a dip portion 58 betweenforehead support portion 46 and a lower portion 60 of support cushion20. Dip portion 58 segregates forehead portion 46 and lower portion 60from each other to provide individual passive adjustment of the twoportions. Dip portion 58 does not need to be in sealing contact with thepatient's facial area. Support cushion 20 further includes a bottomportion 59 having a contoured area that also does not need to be insealing contact with the patient's facial area. The two side areas oflower portion 60 provide most of the support.

Forehead support portion 46 further includes an integrated grooved area62 or pleat defined in side wall 54 of forehead support portion 46 ofsupport cushion 20. Grooved area 62 provides a floating affect toprovide stability. Side wall 54 has an area 64 below grooved area 62that is substantially thicker than the area above it to provide support.A cushion having this type of grooved area is described in co-pendingU.S. provisional patent application Ser. No. 11/312,026, the contents ofwhich are incorporated herein by reference.

In the embodiment illustrated in FIGS. 1-4, seal cushion 18 and supportcushion 20 are coupled together and are coupled to mask shell 22 by amounting member 66. Mounting member 66 has a shape correspondinggenerally to that of support cushion 20 and mask shell 22, and includesa patient side 68 and opposite thereto, an outer side 70 with a sidewall72 therebetween. Outer side 70 includes multiple snap attachmentfeatures 74 a, which are receivable in corresponding snap attachmentfeatures 74 b on patient side 36 of mask shell 22. In the presentembodiment, mounting member 66 is defined from a relative rigidmaterial.

Mounting member 66 includes a forehead portion 76 and a lower portion78. The sidewall 72 of lower portion 78 includes an outwardly extendinglip 80. Sidewall 72 of forehead portion 76 also includes an outwardlyextending lip 82. The inner perimeter of support cushion 20 is coupledto the outer perimeter of mounting member 66, and lips 80, 82 areinsertable into corresponding grooves provided on forehead portion 46and lower portion 60 of support cushion 20. These grooves correspond togrooves 84, 85 shown in FIG. 6. The present invention contemplates usingany suitable numbers of snap attachment features and other mechanical ornon-mechanical means for attaching the mounting member to mask shell 22.The present invention further contemplates other mechanical ornon-mechanical means for attaching support cushion 20 to mounting member66, such as by gluing.

Mounting member 66 further includes a triangular-shaped angled wall 86extending from its patient side. Angled wall 86 is insertable into theinterior of base portion 32 of seal cushion 18 to secure the sealcushion to the mounting member. The present invention contemplates othermechanical or non-mechanical means for attaching seal cushion 18 tomounting member 66 such as by gluing.

The arrangement between mounting member 66 and mask shell 22 provides areservoir 69 between these two elements. This reservoir effectivelyfunctions as a water trap for any water or other fluid that may enterthe mask from conduit 14. This is perhaps best illustrated in FIG. 8.Water or other fluid may condense on the walls of conduit 14, especiallywhen a humidifier is used in the pressure/flow generating system. Thisfluid may flow toward the mask as indicated by arrow A and collect inreservoir 69. Thus, reservoir 69 effectively functions as a water trapto prevent or minimize the change of fluid contacting the user. A maskhaving such features is disclosed in copending U.S. provisional patentapplication Ser. No. 11/300,052, the contents of which are incorporatedherein by reference.

An alternative exemplary embodiment of a patient interface device 87according to the principles of the present invention is illustrated inFIGS. 5-8. In this embodiment, many features are similar to thoseillustrated in FIGS. 1-4. Thus, the description of this embodiment willfocus primarily on the features of the patient interface device uniqueto each embodiment. This alternative embodiment is provided primarily toshow a different possible configuration for coupling the cushions to themask shell. It is to be understood, however, that the present inventioncontemplates other configurations for the patient interface componentsand mixing and matching of the features of the patient interface devicesillustrated in all of these embodiments.

Like in the embodiment of FIGS. 1-4, patient interface device 87includes a seal cushion 18, support cushion 20, and a mask shell 22. Inthis exemplary embodiment, seal cushion 18 and support cushion 20 arecoupled together and to mask shell 22 by a rigid holding member 88, aretaining ring 90, and a flexible connecting member or rolling diaphragm100. Rolling diaphragm 100 corresponds to the rolling diaphragmdisclosed in co-pending U.S. provisional patent application Ser. No.11/374,580 (the '580 application), the contents of which is incorporatedby reference herein.

Rolling diaphragm 100 according to the present invention is operativelyconnected between seal cushion 18 and mask shell 22. In the illustratedembodiment, rolling diaphragm 100 is generally triangular in shape andincludes a substantially concentric outer rim 102 and inner rim 104. Arolling element in the form of a flexible wall or membrane 106 extendsbetween the outer and inner rims. Rolling diaphragm 100 is preferablymolded of a high modulus thermal plastic elastomer or rubbery materialto provide the desired flexibility. The material may be the same ordifferent material than the one used for the seal cushion 18 or supportcushion 20. In the illustrated embodiment, flexible wall or membrane 106has a generally uniform thickness and a substantially U-shapedcross-section when not under pressure, e.g., when a flow of gas is notbeing delivered to the patient interface device. Rolling diaphragm 100changes its shape depending on the force imparted to it through sealcushion 18 or mask shell 22 so that the position of the seal cushionrelative to the mask shell can change. The U-shaped flexible membrane106 is pointed away from mask shell 22.

Rolling diaphragm 100 isolates the forces and acts as a buffer betweenseal cushion 18 and mask shell 22. Rolling diaphragm 100 also acts as aflexible joint allowing relative angular and displacement movementbetween seal cushion 18 and mask shell 22. This allows the seal cushionto self-align on the surface of the patient when the patient interfacedevice is donned by the user. Rolling diaphragm 100 also isolates sealcushion 18 from movement of the patient's head or support cushion 20 anddisplacement of the conduit tubing or headgear.

Outer rim 102 of rolling diaphragm 100 includes an annular flange 108extending substantially perpendicularly from flexible wall membrane 106of rolling diaphragm 100. Rolling diaphragm 100 of this illustratedembodiment further includes a plurality of rectangular holes or slots112 spaced on annular flange 108. Seal cushion 18 is attached to rollingdiaphragm 100 by retaining ring 90, which also has an outer annulargroove 114 for receiving inner rim 104 of rolling diaphragm 100. Holdingmember 88 includes a plurality of snap attachment features 116, some ofwhich are insertable through rectangular holes 112 and then receivablein corresponding snap attachment features 74 c on patient side 36 ofmask shell 22. Other snap attachment features 116 on a forehead portion118 of holding member 88 are receivable directly in the correspondingsnap attachment features 74 d on forehead support portion 40 of maskshell 22.

The present invention contemplates alternative techniques for couplingthe rolling diaphragm to the mask shell, many of which are described inthe '580 application. The present invention further contemplates thatrolling diaphragm 100 can have alternative shapes, can be formed fromdifferent materials or combinations of materials, and/or can havevariations in dimensions over the overall diaphragm. Many suchalternatives are disclosed in the '580 application.

FIGS. 9 and 10 illustrate a third exemplary embodiment of a patientinterface device 120 according to the principles of the presentinvention. In this embodiment, many features are similar to thoseillustrated in FIGS. 1-8. Thus, the description of this embodiment willfocus primarily on the features of the patient interface device uniqueto each embodiment. This alternative embodiment is provided primarily toshow a different possible configuration for the mask shell. Thisembodiment also shows that the cushion inside a cushion arrangement canbe provided without the forehead portion. That is the cushion inside acushion technique can be limited to a seal used to seal the supply ofgas to the user's airway, and need not extend to the forehead as shownin previous embodiments. Again, it should be noted that the presentinvention contemplates other configurations for the patient interfacecomponents and mixing and matching of the features of the patientinterface devices illustrated in all of these embodiments.

Patient interface device 120 includes a mask shell 122 having a foreheadsupport assembly 124. In the illustrated embodiment, forehead support124 includes a support arm 126, a forehead support bracket 128 coupledto the support arm, and a forehead pad 130 coupled to the supportbracket. In the illustrated exemplary embodiment, support arm 126 isadjustably coupled to mask shell 122 such that the arm is movable alongan arcuate path with respect to the mask shell, as indicated by arrow B.This allows the position of the forehead support bracket to be adjustedby the user for optimum comfort. Forehead support bracket 128 is alsomovable relative to the support arm as indicated by arrow C. This allowsthe forehead pad to automatically move the optimum patient contactingposition when the patient interface device is donned by the user.Headgear attachments 132 are provided on each side of the foreheadsupport bracket.

A patient interface device having many similar, if not identicalfeatures (other than the cushion inside a cushion concept of the presentinvention), is described in U.S. patent application Ser. No. 10/654,379(U.S. Pub. No. US-2004-0045551-A1) the contents of which areincorporated herein by reference. It can further be appreciated that theforehead support and the components thereof, can any one of a variety ofdifferent, shapes, sizes, and configurations so long as the foreheadsupport function is achieved. For example, the forehead pad can haveother shapes, materials, combination of materials, sizes, andconfiguration. Similarly, the mask shell can have any one of a varietyof different, shapes, sizes, and configurations, and can includeadditional features, such as headgear attachment portions, one or moreexhaust assemblies, patient circuit connectors, or any combinationthereof. Moreover, the present invention also contemplates a rigidcoupling between support arm 126 and mask shell 122, between support arm126 and support bracket 128, or both.

The present invention also contemplates eliminating the forehead supportentirely, so that the patient interface device is supported on thepatient by a cushion assembly 134, which is attached to the mask shell.If the forehead support is eliminated, a headgear attachment can beprovided at the upper apex of the mask shell. The present invention alsocontemplates providing a post or other protrusion at the upper portionof the shell, i.e., the portion overlying the bridge of the nose, towhich the headgear can be attached.

The present invention further contemplated providing a chin supportassembly (not shown) that extends from the mask shell and contacts theuser's chin or mandible. The chin support assembly can be have the sameor a similar configuration to the forehead support, but extending fromthe lower portion of the mask to contact the user below the lips, i.e.,on the chin or mandible. U.S. patent application Ser. No. 10/953,642(U.S. Pub. No. US-2005-0072428-A1), the contents of which areincorporated herein by reference, describes examples of such chinsupport assemblies suitable for use in the present invention. The chinsupport assembly can be used alone or in combination with the foreheadsupport assembly.

A cushion assembly 134 is coupled to mask shell 122. Cushion assembly134 corresponds to any of the cushion assemblies described above, andincludes an inner seal member or seal cushion 136 and an outer supportmember or support cushion 138. The seal cushion and support cushion canbe coupled together using any of the techniques described herein,including a relatively rigid attachment (see FIG. 1-4) or a flexibleattachment (see FIGS. 5-8).

FIG. 11 is a detailed sectional view showing another technique forattaching a seal member 150 to a flexible connecting member 152. In thisembodiment, the seal member is molded or otherwise bonded to a seal ring154, and the flexible connecting member is molded or otherwise bonded toa connecting member ring 156. In an exemplary embodiment, the presentinvention contemplates overmolding seal 150 on ring 154 and overmoldingflexible connecting member 152 on connecting member ring 156. Seal ring154 and connecting member ring 156 are sized, configured, and arrangedsuch that a wall of the seal ring abuts or is close to a wall of theconnecting member ring at a junction indicated by reference numeral 158.These walls are joined together using any conventional technique, suchas sonic welding. Of course, friction alone can be used to maintain therings in an assembled relation. It is to be understood that otherconfigurations for the rings and ring/seal or ring/flexible membercoupling are contemplated by the present invention.

A fourth embodiment of a patient interface device 200 according to theprinciples of the present invention is illustrated in FIG. 12. Patientinterface device 200 is generally similar to that shown in FIG. 8 exceptfor the at rest positioning of seal cushion 218 relative to supportcushion 220. In this exemplary embodiment, seal cushion 218 is definedin a plane 216 that is disposed at an angle θ with respect to a plane219 defined by another portion of the patient interface device, such asshell 222 or support cushion 220. This is done to preposition sealcushion 218 so that the angle of attack on the face of the user isoptimized. In an exemplary embodiment of the present invention, angle θranges from zero to fifteen degrees (0-15°). In this embodiment, theangle is provided by configuring a rolling diaphragm 230 in such a waythat causes the tilt. Of course, other techniques for controlling theposition of and/or pre-positioning the seal cushion relative to thesupport cushion, the shell, or other portion of the patient interfacedevice are contemplated by the present invention.

In the illustrated embodiments, the seal cushion and support cushion areconfigured/arranged such that an outer (distal) edge of the seal cushionextends beyond the outer (distal) edge of the support cushion. Thisprotrusion of the seal cushion out from the rim of the support cushionis illustrated by distance x in FIG. 8. It should be understood,however, that the present invention also contemplatesconfiguring/arranging the seal cushion and support cushion such that theseal cushion does not extend beyond the outer edge of the supportcushion in the at rest (non-deflected) position.

The patient interface device or any or all of the embodiments of thepresent invention communicates a flow of breathing gas between thepatient's airway and pressure generating device 12, such as aventilator, CPAP device, or variable pressure device, e.g., anauto-titrating pressure support device or a BiPAP® device manufacturedand distributed by Respironics, Inc. of Pittsburgh, Pa., in which thepressure provided to the patient varies with the patient's respiratorycycle so that a higher pressure is delivered during inspiration thanduring expiration or an auto-titratition pressure support system wherethe pressure varies with the condition of the patient, such as whetherthe patient is snoring or experiencing an apnea or hypopnea.

Communicating a flow of breathing gas between the patient's airway and apressure/flow generating device 12 includes delivering a flow ofbreathing gas to the patient from the pressure generating device 12 andexhausting a flow of gas from the patient to ambient atmosphere in thecase of single-limb circuit. The system for delivering a pressurizedflow of breathing gas to a patient according to the present inventioncomprises a pressure or gas flow generating device 12 that produces aflow of gas, a conduit 14 having a first end portion operatively coupledto the gas flow generating device 12 and a second end portion, whereinconduit 14 carries the flow of gas from gas flow generating device 12during operation of the system; a patient interface device 10 coupled tothe second end portion of the conduit; and a headgear. The interior ofseal cushion 18 is exposed to the pressurized breathable gas. It is tobe understood that other accessories used in a pressure support system,such as a humidifier, pressure sensor, flow sensor, temperature sensor,humidity sensor, bacteria filter, etc. can be used in conjunction withthe patient interface device of the present invention.

It can also be appreciated that the description of the presentinvention, while discussing some different embodiments for the seal andmask, is not intended to be an exhaustive listing of the seals and maskssuitable for use with the patient interface device of the presentinvention. On the contrary, those skilled in the art can appreciate thatthe mask shell, the seal cushion, the support cushion, and thecomponents used to connect these elements to one another can have almostany configuration or size and still be used in conjunction with thepatient interface device of the present invention.

It should be understood that the present invention contemplates that theseal cushion and the support cushion can a variety of configurations,including those of conventional cushions. For example, the presentinvention contemplates from either of these cushions from a gelmaterial, as disclosed, for example, in U.S. Pat. Nos. 5,647,357 and5,884,624, the contents of which are incorporated herein by reference,or from a gel material that is customizable, as disclosed, for example,in U.S. Pat. No. 6,397,847, the contents of which are incorporatedherein by reference. The present invention also contemplates that sealcushion, the support cushion, or both can be an air-filled cushion andcan include an optional sealing flap. See, e.g., U.S. Pat. No.4,791,051. These cushions can include features typically found inconventional cushion, such as stiffening devices, materials, and/orgeometries and can be formed from any one of a variety of materials,such as silicone, or a combination of materials.

Although the invention has been described in detail for the purpose ofillustration based on what is currently considered to be the mostpractical and preferred embodiments, it is to be understood that suchdetail is solely for that purpose and that the invention is not limitedto the disclosed embodiments, but, on the contrary, is intended to covermodifications and equivalent arrangements that are within the spirit andscope of the appended claims. For example, it is to be understood thatthe present invention contemplates that, to the extent possible, one ormore features of any embodiment can be combined with one or morefeatures of any other embodiment.

What is claimed is:
 1. A patient interface device for use in deliveringa flow of gas to an airway of a patient, the patient interface devicecomprising: a mask shell having a patient side and an outer sideopposite the patient side adapted for receiving a flow of gas; a sealcushion including a first end portion defining a first perimeter andadapted to contact a first area of a patient's face to substantiallyseal therewith, and a second end portion opposite the first end portion,wherein a cavity is defined by the seal cushion, the cavity beingadapted to receive a portion of the patient's face, and wherein the flowof gas communicates with the cavity; and a support cushion having afirst end portion disposed outside at least a portion of the firstperimeter and adapted to contact a second area of a patient's face and asecond end portion opposite the first end portion, wherein the supportcushion is separate and non-unitary with the seal cushion, and whereinthe second end portion of the seal cushion and the second end portion ofthe support cushion are coupled to the patient side of the mask shell.2. The patient interface device of claim 1, wherein the support cushionfurther comprises a forehead support portion.
 3. The patient interfacedevice of claim 1, further comprising a flexible connecting memberpositioned between the patient side of the mask shell and the second endportion of the seal cushion to allow angular movement between the sealcushion and the mask shell.
 4. The patient interface device of claim 1,wherein the seal cushion, the support cushion, or both include a groovedarea defined in a portion thereof.
 5. The patient interface device ofclaim 1, wherein the first end portion of the seal cushion, the firstend portion of the support cushion, or both include: (a) at least oneflap, (b) two flaps at least partially overlying one another, (c) a gasfilled cushion, (d) a gel material, or (e) any combination thereof. 6.The patient interface device of claim 1, wherein the first end portionof the seal cushion, the first end portion of the support cushion, orboth are contoured.
 7. The patient interface device of claim 1, furthercomprising a connecting member coupling the mask shell with the sealcushion, and wherein a reservoir is defined between the connectingmember and the mask shell.
 8. A system for delivering a flow of gas to apatient, comprising: (a) a gas flow generating device that produces aflow of gas; (b) a conduit having a first end portion operativelycoupled to the gas flow generating device and a second end portion,wherein the conduit carries the flow of gas from the gas flow generatingdevice during operation of the system; and (c) a patient interfacedevice comprising: (1) a mask shell having a patient side and an outerside opposite the patient side, wherein the second end portion of theconduit is coupled to the mask shell, (2) a seal cushion including afirst end portion defining a first perimeter and adapted to contact afirst area of a patient's face to substantially seal therewith, and asecond end portion opposite the first end portion, wherein a cavity isdefined by the seal cushion, the cavity being adapted to receive aportion of the patient's face, and wherein the flow of gas communicateswith the cavity; and (3) a support cushion having a first end portiondisposed outside at least a portion of the first perimeter and adaptedto contact a second area of a patient's face and a second end portionopposite the first end portion, wherein the support cushion is separateand non-unitary with the seal cushion, and wherein the second endportion of the seal cushion and the second end portion of the supportcushion are coupled to the patient side of the mask shell.
 9. The systemof claim 8, wherein the support cushion further comprises a foreheadsupport portion.
 10. The system of claim 8, further comprising aflexible connecting member positioned between the patient side of themask shell and the second end portion of the seal cushion allowingangular movement between the seal cushion and the mask shell.
 11. Thesystem of claim 8, wherein the seal cushion, the support cushion, orboth include a grooved area defined in a portion thereof.
 12. The systemof claim 8, wherein the first end portion of the seal cushion, the firstend portion of the support cushion, or both include a rim, multiplerims, and gas filled cushion, a gel material, or any combination thereof13. The system of claim 8, wherein the first end portion of the sealcushion, the first end portion of the support cushion, or both arecontoured.
 14. A patient interface device for use in delivering a flowof gas to an airway of a patient, the patient interface devicecomprising: a mask shell having a patient side and an outer sideopposite the patient side adapted for receiving a flow of gas; a sealcushion having a first end portion defining a first perimeter andadapted to contact a first area of a patient's face to substantiallyseal therewith, a second end portion opposite the first end portion,wherein a cavity is defined by the seal cushion, the cavity beingadapted to receive a portion of the patient's face, wherein the flow ofgas communicates with the cavity, and wherein the seal cushion overliesa first area on such patient when donned by such a patient; and asupport cushion having a first end portion disposed outside at least aportion of the first perimeter and adapted to contact a second area of apatient's face and a second end portion opposite the first end portion,wherein the support cushion is separate and non-unitary with the sealcushion, wherein the second end portion of the seal cushion and thesecond end portion of the support cushion are coupled to the patientside of the mask shell, wherein the support cushion overlies a secondarea on such patient when donned by such a patient generally proximateto the first area.
 15. The patient interface device of claim 14, whereinthe support cushion further comprises a forehead support portion. 16.The patient interface device of claim 14, further comprising a flexibleconnecting member positioned between the patient side of the mask shelland the second end portion of the seal cushion allowing angular movementbetween the seal cushion and the mask shell.
 17. The patient interfacedevice of claim 14, wherein the seal cushion, the support cushion, orboth include a grooved area defined in a portion thereof.
 18. Thepatient interface device of claim 14, wherein the first end portion ofthe seal cushion, the first end portion of the support cushion, or bothinclude a rim, multiple rims, and gas filled cushion, a gel material, orany combination thereof.
 19. The patient interface device of claim 14,wherein the first end portion of the seal cushion, the first end portionof the support cushion, or both are contoured.